This invention relates to plastic pipes comprising an inner wall and an outer wall which are interconnected by lengthwise extending connecting partitions forming lengthwise extending channels.
Such plastic pipes with lengthwise extending channels which are delimited by an inner and an outer wall are known per se.
When in use in pipe lines, the outer wall may be damaged so that ground water can penetrate through openings or cracks in said outer wall into the lengthwise extending channels. This groundwater then mixes with waste liquids transmitted by the aforementioned pipe lines.
Plants for sewage purification which purify the sewage water supplied by the pipe lines can thus be loaded with large quantities of groundwater which need not be purified.
In case of damage or openings in the outer wall, waste water from the pipe lines may also flow into the continuous channels and issue via these continuous channels and openings or cracks in the outer wall, which gives rise to serious pollution of the soil.